Introduction to Knowledge Graphs (2): OWL-based Knowledge Graphs

December 20, 2025

Lecture Slide

Note: This is my own interpretation based on self-study of the lecture slides. While I’ve tried to be accurate, some of my commentary and understanding may be imperfect.

Ontology

Consider the first example. KG Triples :london :location :england DL Syntax: location (london, england) Semantics <$\text{london^{I}}, \text{england^{I}}$> $\in$ $\text{location}^{I}$

Layer Representation Reads as
Storage :london :location :england edge from london to england labeled location
Logic location(london, england) london and england satisfy the location relation
Representation $\langle \text{london}^I, \text{england}^I \rangle \in \text{location}^I$ In this interpretation, London-England pair belongs to location relationships

OWL 2 Entities

classes and individuals

owl:Class is used to represent classes, which is a set of individuals. owl:NamedIndividual is used to represent individuals.

Top and Bottom Classes

Things to Add

  1. visualisation of OWL 2 entities

References

  1. Lecture Slide
  2. OWL Web Ontology Language Reference
  3. Description Logics
  4. Description Logics:ALC